Many apartments, houses, offices, and factories have central air circulation, so that the various rooms and similar enclosures receive warmed, cooled, or otherwise conditioned air not only from their own individual locations but from anywhere in the circulation path. Unless scrupulously cleaned--the rare exception--recirculated air carries contaminants from any room to many or most (if not all) of the other rooms to and from which it is recirculated. Smoking in any room can easily contaminate others, as can cleaning circuit boards with trichloroethylene, for example. This is a bad problem.
For many years, green plants have been considered beneficial to their environment, in that they take up carbon dioxide and give off oxygen. Potting soil or similar medium is customary as a nurturant. Activated carbon has long been known to adsorb onto its extensive surface a wide variety of contaminants form and may be included in potting medium for its effect upon liquid or gaseous contaminants.
Combination of such capabilities has been suggested heretofore, as referenced in my aforementioned patent application, but without practical success theretofore as to the air in rooms, much less as to air supplied to rooms from a circulating system, for example. It has remained for the present inventor to extend such teachings so as to achieve practical success in such purification, as below.